PSYC2050 - Wk7 Attention and Working Memory Flashcards
Why do we have an attentional blink and what does it tell is about cognitive capacities?
There is a hard limit
What is a switch cost ?
Time (and maybe error) cost when switching tasks
Where is task switching happening in the brain?
PFC
Explain the idea of “task set”?
Preparation to perform one task rather than another
what are two processes which may invoke a switch cost?
Establishing an appropriate task set; and disengaging an inappropriate set
How much was the severe switch cost observed by Jersild (1927)?
Up to several hundred ms
What is the purpose of AABB or AAABBB switch task designs?
match practice and fatigue over trials.
In task switching experiments, what happens if both stimuli and responses are different from each other?
There are small switch costs (eg. A number task alternated with a word task)
What happens to switch costs when a common stimulus configuration is used to determine the the task and response selection rule?
There is a major cost involved in switching between similar tasks and response cues
Do people occasionally forget what task is next and does that explain task switch costs? What do we see?
No, there is no evidence of occasional slow trials affecting switch. Instead a general slowing of the RT distribution
What did Rogers & Monsell find about switch cost over two days of trials? 3
Day 2 performance improved.
Large switch cost despite predictability and practice.
Similar difficulty for letter and digit tasks.
Does practice eliminate switch costs?
No
How does task difficultly affect switch cost? Why?
When switching from a hard task to an easy task there is greater cost. Harder to disengage from a more demanding task.
does preparation time reduce task switching costs?
Yes more time to prepare increased reaction speed.
Does task-cueing eliminate switch costs?
No, they are reduced but not eliminated.
How doe we know whether it is preparation time or delay from last trial which reduces switch cost? [3: design, findings, meaning]
Meiran (1996) varied cue-to-next-stimulus and last-response-to-cue interval. Short cue to stimulus interval led to large cost even when there was a long delay from the last trial. This implicates active preparation
What does active preparation involve?
Both disengaging the past task and engaging the coming task
Can preparation remove switch costs entirely?
No there is always a residual cost
Why are residual costs (in task switching) regarded as exogenous effects?
They are stimulus driven because you can’t do any decision-making for the next trial until the stimulus has been presented and identified.
How do theories various theories approach switch cost? 3
- The role of active preparation (endogenous)
- the role of interference effects from past task (disengagement)
- Whether exogenous factors play a role
What is disengagement theory?
The past task set interferes because it is not adequately disengaged.
Why is disengagement theory not correct?
Evidence showing the role of active preparation even when decay time is controlled.
What is the endogenous + exogenous theory (Rogers & Monsell)? 2
- Endogenous preparation requires time
2. Residual cost is explained by exogenous component of task set which is triggered only by suitable stimuli
What is the endogenous only theory of switch costs?
The residual cost only arises because people do not prepare adequately on every trial. There is no exogenous factor playing a role.
What is the best theory of task switch costs and why?
Endogenous + exogenous; even when endogenous factors are addressed the lab, the residual switch cost remains.
What is Kahneman’s capacity theory?
Over-learned tasks become more automatic and consume fewer resources
How does Kahneman believe automaticity is accomplished?
Restructuring and co-ordination of concurrent tasks reduces interference from sub tasks on each other.
How do Shiffrin & Schneider demonstrate automaticity? [3: task, design, findings]
Ps had to search for target letters in RSVP. 2 conditions: categorical and mixed sets, set size = 2 or 4. for categorical practice eliminates difference for set size. For mixed, set size has an effect regardless of practice.
What is the difference between mixed and categorical memory sets?
Targets can be distractors; or targets are always the same.
Where do we see automaticity in the lab, using the Shiffrin and Schneider paradigm?
When search targets were consistent people became good at the task regardless of set size. But when targets were variable (distractors or target for any trial) set size always had differences. This show the latter was always harder.
What are the characteristics of automatic processes?
- Without awareness
- Without conscious deliberation/obligatory
- Without expenditure of resources
- Fast
- Rigid/habitual
What is a good example of a process which is rigid and habitual (automatic response)?
Reading
How practice lead to automaticity according to Logan (1988)? What does this mean automaticity is?
It leads to storage of information about the stimulus and how to respond. So automaticity is based on knowledge acquisition, storage, and retrieval.
What are problems with traditional criteria for automaticity? 2
Many automatic processes dont meet all the criteria. Even well-practised tasks are impacted by task load.
How does awareness interact with automaticity? 2
You can intend to perform a task but not be aware of how you are performing it. You can be aware of task but not intend to do it (driving wrong turn)
Does automaticity depend on the situation?
Yes
What is working memory?
Where attention meets memory
What is working memory involved in? 3
Conscious thought, decision making, directing attention
What is the capacity of working memory?
7 .. ish
What are the components of Baddeley’s WM model?
Central executive:
- phonological loop
- Visio-spatial sketchpad
- episodic buffer
What does the central executive part of the WM model do?
Co-ordinates activity of subordinate systems that store info
Does the central executive have its own storage capacity?
No
What are some functions of the Central Executive? 4
- Coordinate subsidiary WM systems
- Control of encoding and retrieval strategies
- switching attention
- Mental manipulation of material in slave systems
What is a task that uses the Central executive, which you could use to “occupy” the CE? What happens to this task when there are lots of demands on CE?
Random number/letter generation. This becomes less random under concurrent CE demands
What are the two components of the phonological loop?
Verbal store (inner ear) Subvocal articulatory rehearsal process (inner voice)
How long does information last without rehearsal?
About 2 seconds, unless maintained
What are the 4 effects which show the phonological loop?
- Phonological similarity effect
- Irrelevant speech effect
- Word Length effect
- Concurrent articulation effect
What happens in the phonological similarity effect?
Harder to remember the ORDER of words that sound similar
What is the irrelevant speech effect? What does this mean?
Speech impairs serial verbal recall of visually presented material. Hearing speech automatically takes up the phonological loop.
What is the word length effect?
Longer spoken duration makes things harder to remember.
Is the word length effect due to number of syllables?
No, more related to how long it takes to say it
What is an alternative view on the word length effect? Why is wrong?
Cowan: you forget the words because they take longer to recall. But, word length effects still present with probed recall. (Ie was the word in position x?)
What is concurrent articulation (or articulatory suppression)?
Articulating sounds takes up the phonological loop, making it harder use it to encode info in WM
What are two ways concurrent articulation affects WM?
Eliminates subvocal rehearsal
Impairs phonological recoding of visual material
Does silent articulation have a suppressive effect on WM? What about similar non-speech actions?
Yes, but chewing doesn’t (so its not just the action, its the inner voice)
Is the phonological loop necessary for comprehending written and oral language?
No, even brain injured patients can understand and read language.
What is phonological loop important for?
Vocabulary learning in children
What is the corsi tapping task?
A person has to remember and repeat a sequence of objects which are tapped (in order)
Does concurrent speech interfere with V-S tasks?
No, speech only impairs verbal encoding of shapes
What are two components of the V-S sketchpad?
Visual cache which stores patterns
Inner-scribe (spatial rehearsal/movement)
Can blind people use the V-S sketchpad?
Yes they can still rehearse spatial tasks
What are 5 processes the V-S sketchpad is involved in?
- Planning & executing spatial tasks
- Manipulating visual images
- Tracking changes in perceptual world
- Maintaining orientation & directing movement
- Comprehending certain verbal info (eg navigation)
What are two things that the Baddeley model of WM describes and organises? And what does it lack? 2
Limitations of memory
Coding and modality effects
How do stores interact and how do things get into LTM?
What are two models which explain why there is a limit on visual working memory? Which model is favoured and why?
Slot model: fixed # of object representations
Resource model: limited representational medium - items which take up more resource, stored with less noise
Effects of complexity on capacity favour resource model.
How do you investigate which areas of the brain are involved in visual working memory?
The load effects in a RSVP task (which uses articulatory suppression) are correlated with brain activation which also shows load related activation.
Is VSTM/VWM specific or distributed amongst brain areas?
Lots of brain areas are implicated in visual working memory
